Sewer backwater valves
Most properties are connected to public (mainline) sewers. The majority of these properties have been built so that an obstruction in the public sewer will not cause sewage backup into the property.
Other properties, however, require the protection of a backwater valve in the owner's drain line. These properties have been built (see diagram) so that the drain of the lowest plumbing fixture (bath tub, shower, etc.) is lower than the upper manhole (maintenance hole) of the public sewer. The backwater valve is designed to automatically shut to prevent sewage from backing up into the building from an obstructed public sewer.
If your property appears to require a backwater valve, but you do not know if one has been installed, we strongly encourage you to call a licensed plumber, who can evaluate your situation and, if necessary, install a backwater valve. Backwater valves must be checked to ensure that they are operating properly at all times. Root cleaning machines, debris in the drain line or other problems can easily damage or interfere with the proper operation of backwater valves.
A plumbing permit is required for the installation of a backwater valve. See http://www.ladbs.org/about_us/csc.htm to get more information.
To report spills, call
Evening hours, call